Age of Mammals, Cenozoic, Cenozoic era - approximately the last 63 million years

Holocene, Holocene epoch, Recent epoch - approximately the last 10,000 years

Pleistocene, Pleistocene epoch, Glacial epoch - from two million to 11 thousand years ago; extensive glaciation of the northern hemisphere; the time of human evolution

geological period, period - a unit of geological time during which a system of rocks formed; "ganoid fishes swarmed during the earlier geological periods"

digit, figure - one of the elements that collectively form a system of numbers; "0 and 1 are digits"

multiple - having or involving or consisting of more than one part or entity or individual; "multiple birth"; "multiple ownership"; "made multiple copies of the speech"; "his multiple achievements in public life"; "her multiple personalities"; "a pineapple is a multiple fruit"

ordinal - being or denoting a numerical order in a series; "ordinal numbers"; "held an ordinal rank of seventh"